bentley



(No ModeL) 3 Shets-Sheet 1.- R. BENTLEY & T. FORD.

GUT-OFF VALVE.

No. 380,474. Patented A r. 3, E1888.

2 j Q It w I ll! 0 1 4 N i Z 2% Y -O g Y l WITNESSES IfVEiITOR M i BY ATTORNEYS.

(No Model.) 3 Sheets-Sheet 2. R. BENTLEY & T. FORD.

CUT-OFF VALVE. I No. 380,474. Patent dApr. 3, 1888.

ATTORNEYS.

(No Model.) 3 Sheets-Sheet s. R. BENTLEY & T. FORD.

OUT-OFF VALVE. Y No. 380,474. Patented Apr. 8, 1888.

WITNES w lhvrrnn STATES PATENT Orrrcn.

ROLAND BENTLEY, OF DRESDEN, AND THOMAS FORD, OF LONGTON, COUNTY OF STAFFORD, ENGLAND.

CUT-OFF VALVE.

SPECIFICATION forming part of Letters Patent No. 380,474, dated April 3, 1888.

. Application filed May 31, 188?. Serial No. 939,801. (No model.) Patented in England June 8, 1895, No. 6,897, and in Belgium September 25, 1886, No. 74,641.

To aZZ whom, it may concern.-

Be it known that we, ROLAND BENTLEY, of Dresden, in the county of Statford, England, and THOMAS F0121), of Longton, in the county of Stafiord,England, have invented a new and Improved CutOffValve, of which the following is a full, clear, and exact description.

Our invention relates to an equilibrium slide-valve for steam, air, and water engines, with an automatic variable cut-off or expansion valve applicable to steam and air engines.

This invention consists of an equilibrium hollow cylindrical slide-valve worked by an eccentric from the main shaft, as in the ordinary way,with cylindrical valveinclosed therein and worked by an eccentric and governors or otherwise, and intended to act as an automatic variable cut-off or expansion valve.

The main valve is fitted in the cylindrical valve-chest, the passages of which are placed in a diagonal or oblique form, the object of which is to quicken the variation of the ex pension-valve; but we claim the right of using either diagonal or parallel passages, as the main valve may be used either with or without the variable expansion-valve. The variable eXpansion-valve, being fitted inside the main valve, travels inside the same and cuts off the steam to engine by a rotary motion given to it by the governor, to which provision is attached for adjustment at will, or by any other application or arrangement we may think fit to adopt to work the expansionvalve.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar letters of reference indicate corresponding parts in all the figures.

Figure 1 is a central sectional view of our improved valve, representing the same as arranged in connection with the steam-chest of a cylinder, which steamchest and cylinder are also shown in section, the view being taken in line :0 cv of Fig. 4. Fig. 2 is a sectional view of the steam-chest with the valve removed. Fig. 3 is a view of the inner or cutoff valve. Fig. 4 is an end view of the cylinder and steamchest, and Fig. 5 isa cross sectional view taken on line 1 y of Fig. 1.

Fig. 1 shows asection of cylinder and valvechest and main and cut-off valves through line a: :r, Fig. 4. The steam enters the valvechest I by branch E, Fig. 2, thence into the cylindrical cut off valve B, Fig. 1. After passing through cut-off valve B the steam enters the cylindrical main valve A, thence into the ports J to K into cylinder, and exhausting into port L in valve to port M in cylinder, as in the ordinary way. The valve chest I is truly bored out to receive the main valve A, which is made a perfect sliding fit. The cylindrical main valve A, Fig. 1, has a to-andfro sliding motion imparted to it by spindle C, which is connected to rod worked by an eccentric on the main shaft. The cylindrical cut-oifvalve B, Fig. 1, is properly turned to fit in main valve A, Fig. 1, which receives its sliding motion in a similar manner to the main valve A from a second eccentric on the main shaft, the rod of which is coupled to the spindle F. The spindle F of cut-off valve B has a featherkey sunk in at N, and is secured to valve B by two collars and set-screws or taper pins. The arm X, Fig. l, is cast on the valve chest cover, on which provision is left for receiving brass bush Y, through which the spindle F travels to and fro. At this end of the spindle F there are two feather-keys, which pass through two seats in bush Y. The lever H, being secured to bush Y, when lifted by the governor to which it is attached, gives the rotary motion to cut-off valve B, to which it gives the necessary lap over the oblique ports simultaneously with the sliding motion given to the same by the eccentric on the main shaft.

Fig. 2 shows a section of the cylindrical valve-chest, and shows the oblique ports or passages O P, Fig. 2, which extend nearly half-way round the cylindrical valve-chest. The valve-chest I, Fig. 2, is truly bored between T and U on the top and V and W on the bottom, and vice versa on the other side of the valve-chest, the rest portion of the valve-chest I being cored out to wider diameter to allow the steam to get at the back of the valve, so as to counterbalance the steam in front of it, and thus render the main valve an equilibrium or truly balanced one.

Fig. 3 on the annexed drawings shows the ICO . motion thus varying the cut-off from one-quarter to three-quarters stroke.

We do not claim a cylindrical cut-off valve adapted to rotate within a slide-valve that works on a seat having diagonal ports.

What we claim is The combination of the following elements for the purpose of forming an automatic variable cut-0E or expansion valve, to wit: the main slide-valve A, having the form of a hollow cylinder and provided with diagonal ports, the cylindrical cut-off valve B, constructed with diagonal passages and adapted to fit in said main valve, it also having both sliding and rotary motions therein, and the cylindrically-bored steam-chest having the diagonal steam-ports, and means for operating both valves A and B, all arranged as shown and described.

' ROLAND BENTLEY.

THOMAS FORD.

Vitnesses:

J NO. W. MALLETT, HARRY HOWLETT, Clerks to Messrs. Paddock & Sons, Solicitors, Han- 

